Honeywell SmartPAC 2 User Manual page 373

SmartPAC 2 with WPC Integration
The OSHA Safety Distance Formula
DANGER
!
INCORRECT SAFETY DISTANCE
• Calculate the safety distance carefully according to the instructions below, and mount your
light curtain heads at least this distance from the hazardous area.
• Mount your light curtain heads at least 7.5" (191 mm) from the hazardous area, regardless of
the calculated safety distance.
• Be sure your value for T s includes the response times of all devices that react to stop the
press. If your measurement of stop time does not include response time of the press control,
light curtain, and any other devices that react to stop the press, the safety distance will be
too short.
Failure to comply with these instructions will result in death or serious injury.
DANGER
!
STOPPING TIME TOO LONG
Use a brake monitor where a light curtain is used to protect operators whose hands are
routinely exposed to a hazardous area, as required by OSHA 1910.217 (c) (3) (5). A brake
monitor continually checks that the machine's stopping time does not exceed a
predetermined limit.
Failure to comply with these instructions will result in death or serious injury.
The OSHA safety distance formula as specified in OSHA regulation 1910.217 is explained
below. As noted earlier, Honeywell Wintriss Controls recommends you use the American
National Standards Institute (ANSI) formula for calculating safety distance. It contains more
factors that allow you to calculate the safety distance more precisely. The ANSI formula is
explained in the previous section.
Here is the OSHA formula:
D s = 63 inches/second x T s
D s is safety distance.
63 inches-per-second is the OSHA-recommended hand-speed constant.
T s is the stop time of the press in seconds.
T s is measured at approximately 90° of crankshaft rotation (or at maximum closing velocity).
T s must include all components that are involved in stopping press. It must include response
time of the press control that activates the brake and response time of the light curtain (30 ms
for Shadow V).
In the 90° stop time test using SmartPAC 2, the stop time readout includes the stop time of
the press and response time of the press control. How to do the 90° stop time test is described
earlier in this chapter.
Since some increase in stop time can invariably be anticipated due to clutch/brake system
deterioration, a percentage factor must also be added to the actual measured stop time of your
press when determining your safety distance.
SmartPAC 2 Run Mode Chapter 6
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